During operation of internal combustion engines, exhaust gases may include quench gases from the combustion chamber surfaces and crevice volumes in the spaces between the piston and cylinder wall where unburned fuel, especially unburned air/fuel-mixture, is present after the end of combustion in the engine cylinders. Therefore, it is desired to gain the amount of unburned air/fuel-mixture and to recycle the same during a subsequent combustion cycle.
For example, U.S. Pat. No. 4,191,150 A discloses an engine with selective venting of unburned mixture from the piston crevice volume. Particularly, venting means include one or more bypass channels in the cylinder wall which bypasses the piston rings and connects the crevice volume with the engine crankcase in the lower portions of the piston stroke. The mixture is removed during the latter portion of the power stroke.
U.S. Pat. No. 5,357,919 A discloses a hydrocarbon emission control for a four-stroke spark ignited internal combustion engine having a variable volume chamber and an auxiliary chamber with a fixed volume which is smaller than the maximum volume of the working chamber. The working chamber and the auxiliary chamber are connected to each other by a series of passages in the cylinder wall, wherein the passages in the cylinder wall are situated such that when the piston is near the top of its exhaust stroke, the end gases stored in the auxiliary chamber are discharged into the crankcase.
U.S. Pat. No. 6,431,157 B1 discloses an internal combustion engine comprising a cylinder block with at least one cylinder barrel, a cylinder head with at least one inlet channel and exhaust channel with related inlet and exhaust valves to a combustion chamber situated above a piston moveable in the cylinder barrel and a crankcase for lubricating oil situated below the piston. The piston includes at least two grooves situated at a distance from each other, each having a piston ring and a piston collection chamber contained between the rings.
The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.